NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

What is the primary purpose of a daylight harvesting system?

1. Turns lights on and off based on occupancy

2. Controls lights based on a preset schedule

3. Dims or switches lights based on available daylight

4. None of the above

The correct answer is: Dims or switches lights based on available daylight

The primary purpose of a daylight harvesting system is to dim or switch lights based on the amount of available daylight in a space. This technology is designed to optimize energy use by taking advantage of natural light to illuminate an area, thereby reducing reliance on artificial lighting. By continuously monitoring daylight levels, the system adjusts indoor lighting accordingly, which helps to maintain consistent illumination while minimizing energy consumption. This not only enhances energy efficiency but can also improve overall occupant comfort and well-being. In contrast, a system that only turns lights on and off based on occupancy focuses solely on presence detection and does not consider natural light levels. Additionally, controlling lights based on a preset schedule does not adapt dynamically to changing daylight conditions, which is a core functionality of daylight harvesting systems. Therefore, the ability to respond to ambient light conditions makes this option the most accurate representation of the primary function of a daylight harvesting system.